Has elegance betrayed physics?(physicstoday.scitation.org)
physicstoday.scitation.org
Has elegance betrayed physics?
https://physicstoday.scitation.org/doi/10.1063/PT.3.4022
48 comments
"It's always easy once you know the answer."
The hard part is figuring it out.
The hard part is figuring it out.
I'd also say it's also only easy when you know the right question, often that's the most important step in getting to an interesting answer.
And about what. The scope demarks the domain and defines the concepts. Once you've done that right, the question can be as obvious as 6×7.
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Or maybe reality just isn't elegant.
An analogy would be psychology. The evolutionary path our brains took to develop to their current state is ... ugly. Why should things be different in physics?
An analogy would be psychology. The evolutionary path our brains took to develop to their current state is ... ugly. Why should things be different in physics?
That's certainly possible. It may be that we've lucked out so far, and are about to hit a wall, where things get more and more complex.
Another possibility is that developing the next level of theory, and finding a way to simplify it mathematically, are two different steps.
Another possibility is that developing the next level of theory, and finding a way to simplify it mathematically, are two different steps.
Does evolution affect physics?
There's two different things called physics: first there's the set of concepts, equations, techniques, and models that we as humans use to understand the world. Second, there's the way the actual physical world works.
As a human endeavor to have our brains predict things about the physical world, physics has to "run" on the human brain. In that sense, evolution shapes the physics that humans can conceive and understand. Evolution doesn't change what actually happens physically, so it doesn't affect physics that way.
As a human endeavor to have our brains predict things about the physical world, physics has to "run" on the human brain. In that sense, evolution shapes the physics that humans can conceive and understand. Evolution doesn't change what actually happens physically, so it doesn't affect physics that way.
The tricky part is that your first "physics" (human models) is also a part of the physical world. The human concepts and equations affect what humans do, which changes the physical world. There's a bit of a feedback loop.
Concepts, ideas, equations and models absolutely do change the world, in a very real and physical sense. They do not (probably) affect the fundamental laws of physics, though.
Concepts, ideas, equations and models absolutely do change the world, in a very real and physical sense. They do not (probably) affect the fundamental laws of physics, though.
A good example of such a feedback loop are computers. It is impossible to think of modern physics without them, on the experimental side at least.
Another example are computers themselves. You can't build computers without computers, so they are already kind of building themselves, with us humans using as evolutionary slaves/hosts.
Another example are computers themselves. You can't build computers without computers, so they are already kind of building themselves, with us humans using as evolutionary slaves/hosts.
Computers are involved in the practical side of modern physics, but not in the conceptual side. When it is demonstrated that an algorithm will produce a trust-able result, no reference is made to any "real" aspect of computers. Instead, the algorithms are designed based on symbol manipulation and could just as well be carried out by a platonic physicist writing notes in the Mediterranean sand. The specific details of how computers are actually made impacts the implementation but not the results.
Also referred to as the map and the territory.
In the general sense of "evolution" (moving between states): absolutely! That's pretty much what physics is.
For an extreme example, see Wolfram's theory in New Kind of Science, a (controversial) hypothesis about how laws of physics evolve via cellular automata, simple programs producing complexity.
Even outside of this example, much of what we consider as "our universe" (macroscopically observable patterns and laws) evolved through micro-interactions. It was only last century that matter was discovered to be nothing special, just denser clumps of energy.
If you mean evolution in the strictest biological sense, i.e. a cat deciding to change the universal speed of light… unlikely. Though the connection between consciousness and physical world (objectivity, solipsism) is still a contentious and unsettled area.
For an extreme example, see Wolfram's theory in New Kind of Science, a (controversial) hypothesis about how laws of physics evolve via cellular automata, simple programs producing complexity.
Even outside of this example, much of what we consider as "our universe" (macroscopically observable patterns and laws) evolved through micro-interactions. It was only last century that matter was discovered to be nothing special, just denser clumps of energy.
If you mean evolution in the strictest biological sense, i.e. a cat deciding to change the universal speed of light… unlikely. Though the connection between consciousness and physical world (objectivity, solipsism) is still a contentious and unsettled area.
No it's other way around. Physics sets the foundation for what's possible within evolution. Physics is the foundation for all other sciences.
>>> One of my favorite analogies is that it took humanity more than 1000 years
Nitpicking a bit but I think it took the whole mankind life on earth to create algebra :-) That's hundreds of thousands of years (provided mankind even "starts" somewhere)
Nitpicking a bit but I think it took the whole mankind life on earth to create algebra :-) That's hundreds of thousands of years (provided mankind even "starts" somewhere)
That doesn't seem like that useful an analogy. It took a lot more than a thousand years to invent algebra. It also took a very long time to invent a bunch of things that anyone can understand and use, it's not a measure of their complexity or difficulty - wheels, domesticated cats, corn, pointy sticks, pants, etc.
Beautifully illustrated.
people have used algebra since ancient times. it just took 1000+ years to formalize it in a way that is more concrete
Feynman's Rainbow: A Search for Beauty in Physics and Life is a good read: https://www.amazon.com/Feynmans-Rainbow-Search-Beauty-Physic...
Minor spoiler alert.
Feynman had a strong dislike for string theory, even going so far as to shout at someone "I don't want to talk about string theory!" Presumably, Feynman could sense that this kind of "search for beauty" was against empiricism. I always found it interesting that even back then, when empirical observation seemed to rein supreme, there were those who eschewed it and searched for meaning beyond what nature presents to us.
Minor spoiler alert.
Feynman had a strong dislike for string theory, even going so far as to shout at someone "I don't want to talk about string theory!" Presumably, Feynman could sense that this kind of "search for beauty" was against empiricism. I always found it interesting that even back then, when empirical observation seemed to rein supreme, there were those who eschewed it and searched for meaning beyond what nature presents to us.
As I get older I just get more cranky and tired. The LHC returned a negative result for SUSY, it's time to stop and to just accept that. For heaven's sake, the moment MM started thinking the earth was dragging the ether they should have realized they should stop, and at least history could remember them more fondly.[0]
And we're getting to a point where philosophers are reconsidering Poppler's Criterion? It's time to stop. Every day these people continue publishing about SUSY is a day Young Earth Creationists and Climate Change Deniers can notch down as evidence in their favor.
[0] I think it actually isn't widely known that Michaelson and Morley didn't publish their experiment as evidence against a static ether and instead claimed it validated the "ether dragging" hypothesis.
And we're getting to a point where philosophers are reconsidering Poppler's Criterion? It's time to stop. Every day these people continue publishing about SUSY is a day Young Earth Creationists and Climate Change Deniers can notch down as evidence in their favor.
[0] I think it actually isn't widely known that Michaelson and Morley didn't publish their experiment as evidence against a static ether and instead claimed it validated the "ether dragging" hypothesis.
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I always found the bias towards "beautiful physics" to be odd.
Yes, it's true, Maxwell's equations are simple and elegant and the Lagrangian of the standard model is, well, not. But that does not necessarily mean it's wrong! Nature's ugly sometimes...
Yes, it's true, Maxwell's equations are simple and elegant and the Lagrangian of the standard model is, well, not. But that does not necessarily mean it's wrong! Nature's ugly sometimes...
If you think of the pursuit of new physics as an optimisation problem then the bias toward "beauty" is a guard against overfitting. Additionally, part of being "beautiful" to a physicist means that it gives insight into the "why" of the problem which helps in the pursuit of the next bit of new physics.
Huh? I'm new to much of this but keep thinking the Lagrangian is incredibly elegant: a tool which boils the determination of a physical system's behavior down to minimizing a single definite integral. That takes my breath away.
You're talking about the idea of the Lagrangian, the parent was talking about the specific Lagrangian that describes the standard model of particle physics. If you write it all out it takes about a page.
It's a Frankentheory - a collection of reanimated theory body parts sewn together. I totally get why physicists want something more elegant.
The problems are social. Financialisation means a lot of smart PhDs get hoovered up by Wall St to do (effectively useless) work as quants. At the same time, pressure in academia - also created ultimately by financialisation - has made genuinely original creative work an extremely risky career move.
So PhD advisors are far more likely to say "Don't do that" when a hot prospect says "I want to explore this unusual thing which i found from way back which no one else is looking at."
And the idea that a patent clerk without a formal academic affiliation could publish papers that transform physics has become ridiculous.
Conversely mainstream ideas of questionable value - like string theory - which should only ever have remained a fringe interest have become absolutely central, because they're a relatively easy way for ambitious PhDs aiming for tenure to produce plausible physics-like content.
Science was working pretty well around the turn of the century. Now there's sand in the gears, and the entire machine is in danger of seizing up.
The problems are social. Financialisation means a lot of smart PhDs get hoovered up by Wall St to do (effectively useless) work as quants. At the same time, pressure in academia - also created ultimately by financialisation - has made genuinely original creative work an extremely risky career move.
So PhD advisors are far more likely to say "Don't do that" when a hot prospect says "I want to explore this unusual thing which i found from way back which no one else is looking at."
And the idea that a patent clerk without a formal academic affiliation could publish papers that transform physics has become ridiculous.
Conversely mainstream ideas of questionable value - like string theory - which should only ever have remained a fringe interest have become absolutely central, because they're a relatively easy way for ambitious PhDs aiming for tenure to produce plausible physics-like content.
Science was working pretty well around the turn of the century. Now there's sand in the gears, and the entire machine is in danger of seizing up.
What do you mean by "financilisation?"
Not minimizing the Lagrangian, but finding the extrema.
It certainly has no obligation to appeal to our sensibilities...
Our sensibilities were created by selective pressures that are the direct result of the physical laws of this universe. I don’t think that’s a fluke. I think we are awed by mathematical beauty because it is just as fundamental and profound as it appears.
An objective* way to quantify the elegance and parsimony of a hypothesis is through algorithmic information theory, specifically Kolmogorov complexity.
* Certain conditions apply.
* Certain conditions apply.
Surely the problem is lack of inexplicable data?
e.g. relativity had constant speed of light in all directions.
Sure, we could come up with theories without suc data, but the search space is just too inconceivably big to explore. We need constraints to narrow it down... and to have a reason to think it might be true.
Empirical precedes theoretical.
Sure, we could come up with theories without suc data, but the search space is just too inconceivably big to explore. We need constraints to narrow it down... and to have a reason to think it might be true.
Empirical precedes theoretical.
A couple other threads about Hossenfelder's book:
https://news.ycombinator.com/item?id=17434430
https://news.ycombinator.com/item?id=17326642
https://news.ycombinator.com/item?id=17434430
https://news.ycombinator.com/item?id=17326642
That’s a decent review from Wilczek, who years after LHC started grimly ruling out SUSY models gave a talk about the next hundred years of physics and would speak of nothing but SUSY.
If I wrote a book about theorists who just kept working on the same elegant ideas, Wilczeck would be a source of inspiration.
If I wrote a book about theorists who just kept working on the same elegant ideas, Wilczeck would be a source of inspiration.
Sabine's recent lecture at SFI is worth the watch: https://www.youtube.com/watch?v=QdhKfzABsEQ
The recent claims on math misled physicists is a bit over blown ... as everyone would agree, a true physicist uses math only as a tool for trying to get at the physics in nature ... though a physicist may try to stretch an existing math model of the theory, but that is it ... only as a way to explore ... the final say will still come from how well it fits the behavior of nature ...
Perhaps you're just being incomplete in your final thought there, but I think what you've said as is really exemplifies the problem. Science is not just fitting something to data. Science is about predictions, testability, falsifiability, and more. Give any set of input/output data and you can create some sort of model or regression that fits to that data. But that model does not inherently mean so much, especially as the inputs start to become more complex -- meaning the output might not even be mapping to anything fundamental. I think the article hit most strongly on that with this comment:
"Hossenfelder’s real target, when you strip away some unfortunate terminology, is not beauty but self-satisfaction, which encourages disengagement from reality. That attitude reaches its theoretical apex in the doctrine of “postempirical science,” which argues that social consensus, not experimental evidence, determines scientific validity. Here she quotes physicist George Ellis, rebuking physicists and philosophers who adopt that attitude: “There are physicists now saying we don’t have to test their ideas because they are such good ideas. They’re saying—implicitly or explicitly—that they want to weaken the requirement that theories have to be tested. To my mind that’s a step backward by a thousand years.”"
Much of 'science' now a days has started to veer down the path of pseudoscience, and the path there is paved with regression mapping and 'science' by consensus.
"Hossenfelder’s real target, when you strip away some unfortunate terminology, is not beauty but self-satisfaction, which encourages disengagement from reality. That attitude reaches its theoretical apex in the doctrine of “postempirical science,” which argues that social consensus, not experimental evidence, determines scientific validity. Here she quotes physicist George Ellis, rebuking physicists and philosophers who adopt that attitude: “There are physicists now saying we don’t have to test their ideas because they are such good ideas. They’re saying—implicitly or explicitly—that they want to weaken the requirement that theories have to be tested. To my mind that’s a step backward by a thousand years.”"
Much of 'science' now a days has started to veer down the path of pseudoscience, and the path there is paved with regression mapping and 'science' by consensus.
“In the temple of knowledge, we are the ones digging in the basement, probing the foundations…. And when we find ourselves on to something, we call for experimentalists to unearth deeper layers. In the last century, this division of labor between theorists and experimentalists worked very well. But my generation has been stunningly unsuccessful.”
That's a modern viewpoint. Historically, experimental results preceded theory in physics. That was certainly true for classical physics. The early years of subatomic physics were trying to put some structure around experimental results. Somewhere around 40 years ago, though, things got stuck. Experimental results became much harder to get, as the reachable areas had been explored.
Theory not verified by experiment is useless. Science is prediction, not explanation. (Fred Hoyle, the physicist, wrote that, but he was writing an SF novel at the time.)
That's a modern viewpoint. Historically, experimental results preceded theory in physics. That was certainly true for classical physics. The early years of subatomic physics were trying to put some structure around experimental results. Somewhere around 40 years ago, though, things got stuck. Experimental results became much harder to get, as the reachable areas had been explored.
Theory not verified by experiment is useless. Science is prediction, not explanation. (Fred Hoyle, the physicist, wrote that, but he was writing an SF novel at the time.)
> Frank Wilczek is the Herman Feshbach Professor of Physics at MIT in Cambridge, Massachusetts; founding director of the Tsung-Dao Lee Institute and chief scientist at the Wilczek Quantum Center in Shanghai, China; Distinguished Origins Professor at Arizona State University in Tempe; and a professor of physics at Stockholm University and Nordita, also in Stockholm.
How does one simultaneously hold three professorships?
How does one simultaneously hold three professorships?
Earning a Nobel prize helps.
there might even be something more beautiful that we have not discovered yet.
eigenspace(2)
One of my favorite analogies is that it took humanity more than 1000 years to invent algebra. Now we teach it to schoolchildren.
The lesson is that no matter how proud we are of our progress in a field, the next problem might just be a stumper, and we have no idea how long it will take to solve.
Sometimes I like to bring up the lesson of algebra when talking with managers about project estimates. ;-)